Prevalence of Non-Stenotic (<50%) Carotid Plaques in Acute Ischemic Stroke and Transient Ischemic Attack: A Systematic Review and Meta-Analysis

Abstract Introduction Non-stenotic ( Methods We performed a comprehensive systematic review of the literature and meta-analysis on acute ischemic stroke patients in whom carotid imaging was performed using the MEDLINE, Embase and Cochrane database, including studies published up to December 2019. Keywords were "stroke”, “transient ischemic attack”, “carotid”, “plaque”, “atherosclerosis” and “disease”. Included studies had ≥10 patients with acute ischemic stroke and reported the prevalence of non-stenotic ( Results We included forty-five studies (n = 18304 patients, 48.4% males, mean age 63.6 years) in our meta-analysis. Imaging modalities used were ultrasound (n = 26 studies), CT-angiography (n = 7), magnetic resonance-imaging (n = 8) and catheter angiography (n = 4). The overall prevalence of non-stenotic carotid plaques was 51% (95% CI: 43 - 59). 10 studies included mainly patients with embolic stroke of undetermined source (>50% of all patients). The pooled prevalence of non-stenotic carotid plaques in these studies was 55% (95% CI: 42 - 68). 23 studies explicitly reported ipsilateral non-stenotic carotid plaques, the pooled prevalence of which was 51% (95% CI: 45 - 59). Conclusions In this meta-analysis, non-stenotic carotid plaques were present in more than 50% of all acute ischemic stroke patients, with a slightly higher prevalence in ESUS patients. Given the potential role of non-stenotic carotid plaques in stroke etiology, particularly in ESUS, further research should aim to identify criteria that predict the stroke risk associated with non-stenotic carotid plaques.